¶ 81. {concurring in part and dissenting in part). I agree with the lead opinion that the order of the circuit court should be reversed. Because I disagree with the lead opinion's conclusion that Wis. Stat. § 973.195 should be interpreted to allow a district attorney to veto a petition for sentence adjustment and that the statute so interpreted is constitutional, I conclude that the matter should not be remanded for the circuit court to deny the petition for sentence adjustment. I would, as Justice Crooks explains, remand for the circuit court to exercise its discretion whether to grant the petition for sentence adjustment. I do not address mootness; mootness has not been raised, argued, or briefed.
¶ 82. Because Justices Ann Walsh Bradley, N. Patrick Crooks, and Louis B. Butler join this concurrence/dissent and because Justices Ann Walsh Bradley and Louis B. Butler and I join the concurrence/dissent of Justice N. Patrick Crooks, we four form a majority (1) to declare that Wis. Stat. § 973.195 should be interpreted, to save its constitu*531tionality, so that a circuit court has discretion to consider (but is not bound by) a district attorney's objection to a petition for sentence adjustment, and (2) to declare unconstitutional the lead opinion's interpretation of Wis. Stat. § 973.195 to grant a district attorney a veto power over a petition for sentence adjustment.
¶ 83. The net effect of the two concurring/dissenting opinions is that read together, "shall" is interpreted as directory, thereby giving a circuit court discretion to accept or reject an objection from a district attorney on a petition for sentence adjustment under Wis. Stat. § 973.195. Thus, this cause goes back to the circuit court for a full consideration of the factors set forth in Justice Crooks' concurring opinion.
¶ 84. We conclude that the judicial power is compromised when the district attorney is given the unilateral power to end a circuit court's consideration of an inmate's petition for sentence adjustment. A district attorney's exercise of a core judicial function is barred by the separation of powers doctrine.1
¶ 85. Wisconsin Stat. § 973.195(lr)(c) is unconstitutional if read to grant a district attorney veto power over a petition for sentence adjustment. A district attorney's veto power invades the exclusive core constitutional power of the judiciary to impose a criminal penalty. It empowers an executive branch officer to direct a court decision on the merits of a case, thereby violating the doctrine of separation of powers under the state constitution.2
*532¶ 86. Even if we were to conclude that the statute does not invade the exclusive core constitutional powers of the judiciary, the elimination of a circuit court's power to decide an inmate's petition without the approval of the district attorney is an impermissible burden and substantial interference with the judicial branch's authority.3 The statute interferes with the impartial administration of justice by delegating judicial power to one of the parties in the litigation.
HH
¶ 87. The Wisconsin Constitution vests the legislative power in the two houses of the legislature4 and the executive power in the governor.5 The Wisconsin Constitution vests the judicial power of the state in the unified court system as follows:
The judicial power of this state shall be vested in a unified court system consisting of one supreme court, a court of appeals, a circuit court, such trial courts of general uniform state-wide jurisdiction as the legisla*533ture may create by law, and a municipal court if authorized by the legislature under section 14.6
¶ 88. The doctrine of separation of powers is implicit in the division of governmental powers among the judicial, legislative, and executive branches.7 The principles of separation of powers are easy to state but the boundaries that separate the powers of the three branches are "shadowy and not well defined. It is the duty of the court to define them, and see that they are respected."8
¶ 89. A well-accepted principle is that each branch has exclusive core constitutional powers upon which no other branch may intrude.9 This court explained the exclusive core constitutional powers of each branch more than 70 years ago. This explanation remains good law today: "The co-ordinate branches of the government. . . should not abdicate or permit others to infringe upon such powers as are exclusively committed to them by the constitution."10 As this court has said:
In Wisconsin the jurisdiction and power of the courts is conferred, not by act of the Legislature, but by the *534Constitution itself. While the Legislature may regulate in the public interest the exercise of the judicial power, it cannot, under the guise of regulation, withdraw that power or so limit and circumscribe it as to defeat the constitutional purpose.11
¶ 90. Many powers are not, however, exclusively committed to one of the branches, but are shared powers. The court has admonished that as to shared powers "there should be such generous co-operation as will tend to keep the law responsive to the needs of society."12 With regard to shared powers, the legislature cannot impose an unreasonable burden and substantial interference with the judicial branch's authority.13
¶ 91. Sentencing a defendant is an area of shared responsibility,14 and, broken down to its component parts, requires each of the three branches of government to exercise a core power. The legislature prescribes the penalty and the manner of its enforcement.15 The courts impose the penalty (the sentence). *535The executive branch decides what criminal charges to file, carries out the court-imposed sentence, and grants pardons.16
¶ 92. What is at issue in the present case is not a legislative enactment prescribing a penalty or fixing a sentencing range. Nor is the executive's act of charging, executing the sentence, or granting clemency at issue. Rather, Wis. Stat § 973.195 implicates the court's constitutional power to impose a criminal sentence. And as the lead opinion acknowledges, a circuit court's power to impose a sentence embraces the court's power to modify the sentence. Lead op., ¶ 38. "To reduce a sentence by amendment alters the terms of the judgment itself and is a judicial act as much as the imposition of the sentence in the first instance."17 Wisconsin Stat. § 973.195 involves a court's power to examine the act committed and the person committing it in adjusting a sentence the circuit court has imposed.
¶ 93. The question then is whether a circuit court's power to decide a petitioner's request for sentence adjustment under Wis. Stat. § 973.195 involves an exclusive core judicial power or involves a power shared with district attorneys, members of the executive branch of government. We conclude that this statute overreaches the legislative power to define and punish criminal conduct. Wisconsin Stat. § 973.195 directly affects the judicial branch's role in the sentencing *536process: imposing the sentence penalty and exercising discretion in adjusting the length of a sentence that a court has imposed.
¶ 94. The text of the statute evinces a clear violation of the separation of powers doctrine:
973.195 Sentence Adjustment.18
(lr) Confinement in Prison, (a) An inmate who is serving a sentence... may petition the sentencing court to adjust the sentence ....
(c) Upon receipt of a petition filed under par. (a), the sentencing court may deny the petition or hold the petition for further consideration. If the court holds the petition for further consideration, the court shall notify the district attorney of the inmate's petition. If the district attorney objects to adjustment of the inmate's sentence within 45 days of receiving notification under this paragraph, the court shall deny the inmate's petition.
*537(f) If the sentencing court receives no objection to sentence adjustment from the district attorney under par. (c) or the victim under par. (d) and the court determines that sentence adjustment is in the public interest, the court may adjust the inmate's sentence as provided under par. (g). The court shall include in the record written reasons for any sentence adjustment granted under this subsection.
(i) An inmate may submit only one petition under this subsection for each sentence imposed under s. 973.01.
¶ 95. According to the statute, an inmate first files a petition with the circuit court that originally-sentenced the inmate.19 When an inmate files a petition under Wis. Stat. § 973.195, the inmate is requesting a judicial determination on the merits of the petition, namely that he or she has met one of the criteria in § 973.195(lr)(b).20 If, based on the merits of the petition, the circuit court decides not to grant the petition, *538the proceedings end. The inmate loses. So far so good. No problem.
¶ 96. If, however, a circuit court is considering the possibility of granting the petition, it must notify the district attorney. If the district attorney objects to the circuit court's adjustment of the inmate's sentencing, the circuit court must deny the petition. And once an inmate files under the statute and the district attorney objects to a circuit court's adjustment of the inmate's sentencing, the inmate may never seek another sentence adjustment under Wis. Stat. § 973.195 for that sentence,21 no matter how meritorious his or her claim for relief may be, and even if granting the petition would be in the "interests of justice."22
¶ 97. The fundamental problem with the statute is that it requires the circuit court to render a particular decision, namely a denial of a petition brought by the inmate, not upon the merits of the a petition but upon the decision of a district attorney. And the district attorney's "No adjustment for you!" is final for all time. The district attorney holds the keys to the inmate's ability to get a decision on the merits from the circuit court.
¶ 98. This court has declared numerous times that the power to decide an individual case is an *539exclusive core judicial power. The power to decide a case on the merits is the "essence of the court's function."23 A statute cannot "compel the circuit court to decide a case in a particular way", thus "mandating] the result of the case."24
¶ 99. Several cases, old and of recent vintage, are illustrative of the well-established principles governing the instant statute: the power to decide an individual case is an exclusive core judicial power, and any invasion of the exclusive core constitutional powers of the judiciary violates the doctrine of separation of powers under our state constitution. The legislature cannot compel a circuit court to decide a case in a particular way.
¶ 100. In Davis v. Village of Menasha, 21 Wis. 491, 497 (1867), this court struck down as a violation of separation of powers a law that required a trial court to grant a new trial upon the request of either party if the presiding judge died or left the state before expiration of the time for settling a bill of exceptions. The court invalidated the statute, explaining:
No room is left for the exercise of the judgment and discretion of the court, but the judgment must be set aside and a new trial allowed in the specified case, providing the application is made at the time and in the manner there prescribed. It seems to us that this law, then, may well be held to be the exercise of judicial *540functions, not vested in the legislature, but belonging to another department of the government under our constitution.25
¶ 101. Again, this time in City of Janesville v. Carpenter, 77 Wis. 288, 46 N.W.2d 128 (1890), this court held unconstitutional a statute that required a trial court to issue an injunction, even though the petitioner did not prove damages justifying an injunction. Because the statute "takes away the jurisdiction of the courts to inquire into the facts and determine the necessity and propriety of granting or refusing an injunction," the court held the statute unconstitutional.26
¶ 102. In Thoe v. Chicago, Milwaukee & St. Paul Railway Co., 181 Wis. 456, 195 N.W. 407 (1923), this court held unconstitutional a statute prohibiting a trial court from granting a directed verdict before submitting the case to the jury.27 We said a motion to direct a verdict calls for the exercise of legal judgment, an exercise of judicial power, and is not to be decided by legislative fíat. The court wrote:
Neither has the legislature power to declare in advance that the evidence is legally sufficient in every case. It may or it may not be. Whether it is or not is for the *541court to determine in the exercise of the powers conferred upon it by the constitution. A motion to direct a verdict calls for the exercise of legal judgment by applying the law to the facts of each case. It cannot be done wholesale by legislative fiat.28
¶ 103. In re E.B., 111 Wis. 2d 175, 186, 330 N.W.2d 584 (1983), this court held that the legislature could require a circuit court to give the jury a copy of written instructions but could not mandate reversal if the circuit court did not abide by the statute. "Legislation which mandates automatic reversal of trial court judgments upon [the statute's] violation impermissibly limits and circumscribes judicial power."29
¶ 104. In Joni B. v. State, 202 Wis. 2d 1, 8, 549 N.W.2d 411 (1996), the court held that it was a violation of separation of powers for the legislature to prohibit a court from appointing counsel for anyone other than the child in CHIPS proceedings. The court stated that a circuit court's power to appoint counsel is an inherent power to serve the interests of the circuit court and that a court may use its inherent authority to appoint counsel for the orderly and fair presentation of a case. The legislative enactment impermissibly infringed upon that judicial power.
¶ 105. Because deciding the merits of a case is the essence of a court's function, and because the statute delegates to a district attorney the power to mandate the denial of a petition in each case, we conclude that the legislation in question is an unconstitutional violation of the doctrine of separation of powers.
*542II
¶ 106. To make matters worse, if that is possible, the district attorney has represented the State as its attorney in investigating, charging, and prosecuting the criminal charges against the inmate.30 Once charges are filed, the district attorney becomes the attorney for the State, a party to the criminal proceedings, and is subject to the court's authority.31 Thus the statute allows a circuit court's deliberative process and judgment to be circumvented by one of the parties involved in the litigation: the district attorney.32 The statute allows the district attorney to decide&emdash;unilaterally&emdash;whether an inmate's sentence will be adjusted, and thereby unconstitutionally impairs the judiciary's duty to administer justice impartially, as well as being violative of the separation of powers doctrine.33
*543¶ 107. We know of no other instance in the law in which a party to a judicial proceeding can unilaterally determine the outcome of the proceeding on its merits. Even when a party defaults or concedes the correctness of an opposing party's cause, an independent court decision is required.
¶ 108. Thus, even if we were to conclude that the statute does not invade the exclusive core constitutional powers of the judiciary, the elimination of a circuit court's power to decide an inmate's petition without the approval of the district attorney is an impermissible burden and a substantial interference with the judicial branch's ability to administer justice impartially.34
rH l-H hH
¶ 109. The State argues, and the lead opinion agrees, that Wis. Stat. § 973.195 can be upheld as the equivalent of parole, an executive function that the *544district attorney may exercise. How can that be? Everyone knows that Truth in Sentencing was designed to eliminate parole. In any event, if sentence adjustment is parole, then the circuit court should not be involved. The judicial process ends at sentencing, at which point the executive branch of government takes over and the defendant is "directed to the correctional and rehabilitative process. . . . The judiciary phase of the criminal process — imposing a penalty — is complete."35
¶ 110. Parole is gone under Truth in Sentencing, and more importantly for this case, Wis. Stat. § 973.195 does not resurrect parole. Section 973.195 creates a judicial procedure in which an inmate seeks to have the sentencing court amend the judgment of conviction and have a lesser term of confinement or extended supervision imposed. The United State Supreme Court recognized in 1931 that only the court, not the executive branch, has the power to reduce a sentence by amending the judgment.36
¶ 111. The lead opinion opines that this procedure is constitutional, declaring that the district attorney's permission is just a "condition precedent" that must be met. Lead op., ¶ 51. The lead opinion's reasoning contravenes the clear words of the statute and is without weight. Permission by the prosecutor cannot be said to be a "condition precedent" because the plain text of the statute grants a circuit court power to consider the merits of an inmate's petition even before the district attorney is notified of the petition. If the district attorney's permission were simply a "condition precedent" to the consideration of an inmate's petition, *545the circuit court would be utterly lacking discretion to consider the merits of the petition. The circuit court would have to notify the district attorney immediately upon filing of the petition and await the district attorney's green light to proceed.
¶ 112. But Wis. Stat. § 973.195(lr)(c) explicitly provides otherwise: "Upon receipt of a petition filed under par. (a), the sentencing court may deny the petition or hold the petition for further consideration."37 The plain language grants the circuit court the discretion to consider the merits of an inmate's petition. Only if the sentencing court fails to deny the petition on the merits and holds the petition for further consideration does the district attorney come into play.
¶ 113. This statute granting the district attorney a veto power over a circuit court's decision-making process on an inmate's petition for sentence adjustment is constitutionally over the top.
IV
¶ 114. The lead opinion carefully explains that despite the statute, a circuit court has inherent power over sentence modification.38 We agree with the lead opinion that a circuit court has inherent power over *546sentence modification. In a different sentencing era, this court significantly limited a circuit court's power over sentence modification. Those limitations made sense when the legislature gave the executive branch the power to allow an inmate's early release from incarceration.
¶ 115. Under our decisions that limit a circuit court's inherent power to modify a sentence, a circuit court may modify a sentence when the sentence is unduly harsh or unconscionable or has a legal error or on the basis of a new factor. If there are cases that overturn a sentence on the grounds that the sentence was too harsh or unconscionable they are few and far between. Few cases arise in which a circuit court has committed a legal error in sentencing. If a legal error occurs, clearly the circuit court should amend the sentence.
V
¶ 116. Although the court must take care not to expand the judicial branch's exclusive judicial authority, the lead opinion in this case goes too far the other way.
¶ 117. Eighty years ago this court warned judges of their solemn duty to maintain the boundaries of judicial power unimpaired as follows:
*547[ I]t is the solemn duty of every judge, as a sworn officer of the state, to maintain the boundaries of that power unimpaired.
Courts have not, as some people suppose, any option in the matter. The people through the constitution have vested in the courts certain powers and charged the court with the responsibility for the exercise of those powers. Every judicial officer takes an oath that he [or she] will support and maintain the constitution.. .. [The judicial officer] may not fritter or barter away the power committed to his [or her] hands. He [or she] has assumed a responsibility which must be discharged with the utmost fidelity.39
¶ 118. Sadly, the lead opinion here has willingly conceded to the executive branch the most central aspect of the judiciary's power: the power to render a judgment in a case properly before it.
¶ 119. We therefore write separately on the issue of the unconstitutionality of the statute if it is interpreted as granting a district attorney veto power over a petition for sentence adjustment.
¶ 120. I am authorized to state that Justices ANN WALSH BRADLEY, N. PATRICK CROOKS, and LOUIS B. BUTLER, JR. join this opinion.
1 would treat the district attorney's veto as a severable provision and excise it.
*532The lead opinion goes to great length, making numerous arguments to uphold the statute. I do not undertake an analytical critique of each argument, although I could. The lead opinion builds its case on weak underpinnings, supported by quotations taken out of context. Very little research by a reader will quickly reveal the weaknesses that permeate the lead opinion.
State ex rel. Friedrich v. Dane County Circuit Court, 192 Wis. 2d 1, 14, 531 N.W.2d 32 (1995).
Wis. Const. art. W § 1.
Wis. Const. art. V § 1.
Wis. Const. art. VII, § 2.
Friedrich, 192 Wis. 2d at 15; State v. Holmes, 106 Wis. 2d 31, 38, 68-69, 315 N.W.2d 703 (1982).
Thoe v. Chicago, Milwaukee & St. Paul Ry. Co., 181 Wis. 456, 195 N.W.407 (1923). See also Barland v. Eau Claire County, 216 Wis. 2d 560, 573, 575 N.W.2d 691 (1998); Demmith v. Wisconsin Judicial Conference, 166 Wis. 2d 649, 663, 480 N.W.2d 502 (1992); State v. Holmes, 106 Wis. 2d 31, 42-43, 315 N.W.2d 703 (1982).
In re Complaint Against Grady, 118 Wis. 2d 762, 778, 348 N.W.2d 559 (1984).
Rules of Court Case, 204 Wis. 501, 514, 236 N.W. 717 (1931).
John F. Jelke Co. v. Hill, 208 Wis. 650, 660, 242 N.W. 576 (1932).
Rules of Court Case, 204 Wis. at 514. See also Demmith v. Wis. Judicial Conference, 166 Wis. 2d 649, 663, 480 N.W.2d 502 (1992).
Friedrich, 192 Wis. 2d at 14.
State v. Borrell, 167 Wis. 2d 749, 767, 482 N.W.2d 883 (1992).
State v. Setagord, 211 Wis. 2d 397, 407, 565 N.W.2d 506 (1997) (citing In Matter of Judicial Administration Felony Sentencing Guidelines, 120 Wis. 2d 198, 203, 353 N.W.2d 793 (1984)); State v. Lindsey, 203 Wis. 2d 423, 440-41, 554 N.W.2d 215 (Ct. App. 1996).
Borrell, 167 Wis. 2d at 767.
United States v. Benz, 282 U.S. 304, 311 (1931). See also State v. Nardini, 445 A.2d 304, 312 (Conn. 1982) ("The power [to adjust a sentence under the legislative enactment] ... is in effect only a change of judgment, and for that reason [is] a radically different thing from [executive action upon a sentence, such as a pardon]" (quoted source omitted)).
The lead opinion finds it "significant that § 973.195 is specifically titled 'Sentence adjustment' rather than 'Sentence modification.'" Lead op., ¶ 44. Statutory interpretation has reached a new level if the difference between "sentence modification" and "sentence adjustment" qualifies as "significant." This court, which so frequently resorts to the dictionary for statutory interpretation, fails to look up the words "adjustment" and "modification." If it did, it would find them synonyms. The American Heritage Dictionary of the English Language defines "adjustment" as "a modification, fluctuation, or correction" and "modification as "[a] small alteration, adjustment, or limitation." The American Heritage Dictionary of the English Language 22, 1161 (3d ed. 1992) (emphasis added).
Wis. Stat. § 973.195(1r)(a). It is notable that the petition must be filed with the sentencing court, not just any circuit court. This requirement further supports the notion that sentence adjustment is a continuation of a circuit court's sentencing power.
Wisconsin Stat. § 973.195(1r)(b) reads:
Any of the following is a ground for a petition under par. (a):
1. The inmate's conduct, efforts at and progress in rehabilitation, or participation and progress in education, treatment, or other correction programs since he or she was sentenced.
3. A change in law or procedure related to sentencing or revocation of extended supervision effective after the inmate was sentenced that would have resulted in a shorter term of confinement in prison or, if the inmate was returned to prison upon revocation of extended supervision, a shorter period of confinement in prison *538upon revocation, if the change had been applicable when the inmate was sentenced.
4. The inmate is subject to a sentence of confinement in another state or the inmate is in the United States illegally and may be deported.
5. Sentence adjustment is otherwise in the interests of justice.
Wis. Stat. § 973.195(1r)(i).
Wis. Stat. § 973.195(1r)(b)5.
State v. Mitchell, 144 Wis. 2d 596, 618, 424 N.W.2d 698 (1988) (upholding rape shield statute against a separation of powers attack, but citing four Wisconsin Supreme Court cases for the proposition that a statute's mandating the result in a case is unconstitutional).
Id.
Davis v. Village of Menasha, 21 Wis. 491, 497, (1867).
City of Janesville v. Carpenter, 77 Wis. 288, 301, 46 N.W. 128 (1890), explained:
The legislature usurped the judicial power of the courts by the enactment of this statute. It adjudicates an act unlawful and presumptively injurious and dangerous, which is not and cannot be made to be so without a violation of the constitutional rights of the defendant, and imperatively commands the court to enjoin it without proof that any injury or danger has been or will be caused by it.
Thoe v. Chicago, Milwaukee & St. Paul Ry. Co., 181 Wis. 456, 195 N.W. 407 (1923).
Id. at 465.
In re E.B., 111 Wis. 2d 175, 186, 330 N.W.2d 584 (1983).
Wisconsin Stat. § 973.195 does not state who is a party to the adjustment proceedings other than the inmate if the district attorney does not object to an adjustment.
Once the prosecution has commenced, the case is subject to the court's exclusive authority in many ways. See State v. Prihoda, 2000 WI 123, ¶ 19, 239 Wis. 2d 244, 618 N.W.2d 857 (changes to the sentence portion of a written judgment of conviction can be authorized only by a judge); State v. Comstock, 168 Wis. 2d 915, 927, 485 N.W.2d 354 (1992) (district attorney may not bind a court to a plea agreement, nor may a district attorney amend charges without permission from the court); State v. Johnson, 231 Wis. 2d 58, 64-65, 604 N.W.2d 902 (Ct. App. 1999) (court determines whether probable cause exists to believe the defendant committed the charged crime; if probable cause is lacking, the court dismisses the charge); State v. Dums, 149 Wis. 2d 314, 321-22, 440 N.W.2d 814 (Ct. App. 1989) (district attorney cannot, sua sponte, dismiss charges).
Wis. Stat. § 973.195(1r)(c).
Other state courts have declared invalid a statute giving the prosecutor the ability to veto a court's sentence. See State v. *543Prentiss, 786 P.2d 932, 936 (Ariz. 1989) (statutory provision that allowed a judge to impose an alternative sentence only upon prosecutor's consent was invalid as a violation of separation of powers); People v. Superior Court (On Tai Ho), 520 P.2d 405, 407 (Cal. 1974) (statutory provision that gave prosecutor the power to veto a court's decision to an alternative sentence was an unconstitutional violation of separation of powers); State v. LeCompte, 406 So. 2d 1300, 1311 (La. 1981) (statutory provision that only allowed a judge to reduce a sentence if it was the prosecutor who moved for the change violated separation of powers); State v. Olson, 325 N.W.2d 13, 17-19 (Minn. 1982) (The question presented was: "Can the legislature, having granted authority to the courts to sentence without regard to the mandatory minimum provisions [of the statute], condition that authority upon a discretionary act of the prosecutor?" Id. at 17. The court said no, it violates separation of powers.).
Friedrich, 192 Wis. 2d at 14.
State v. Horn, 226 Wis. 2d 637, 650, 594 N.W.2d 772 (1999).
United States v. Benz, 282 U.S. 304, 311 (1931).
Wis. Stat. § 973.195(lr)(c).
On this basis, the present case is significantly different from the Indiana court of appeals case cited by the lead opinion, Beanblossom v. State, 637 N.E.2d 1345 (Ind. Ct. App. 1994). Lead op., ¶ 69 n.16. In Beanblossom, the court of appeals was very explicit in stating that trial courts in Indiana do not have inherent power to modify a sentence, and that if they did, the result of the case might very well be different. The court said:
*546[The argument that the statute violates the separation of powers] presupposes that the trial court has the inherent power to effect the modification of a sentence and that the statute somehow takes this power away from the court. If the trial court had such inherent authority, then the statute in question might well he considered to have usurped that authority. The case law [in Indiana], however, indicates that the trial court does not have such inherent power under the circumstances.
Beanblossom, 637 N.E.2d at 1347.
Thoe, 181 Wis. at 467-68.